From the Chicago Housing Authority‘s website,
The Plan for Transformation began in 2000 under the leadership of Mayor Richard M. Daley with approval from the U.S. Department of Housing and Urban Development (HUD). It is the largest, most ambitious redevelopment effort of public housing in the United States, with the goal of rehabilitating or redeveloping the entire stock of public housing in Chicago.
Read more about the Plan at thecha.org.